Cornelia Seeberg Achim Steinacker Klaus Reichenberger Stephan Fischer Ralf Steinmetz Individual Tables of Contents in Web-Based Learning Systems. 167-168 HT1999/P167.pdf 1999 conf/ht/99 Hypertext http://doi.acm.org/10.1145/294469.294513 db/conf/ht/ht99.html#SeebergSRFS99